How do dual output synths give stereo width?

Hey guys,

lately I've been asking a lot of questions, and trying to understand stereo width better. I have been struggling with guitar width and grasping that it is a mono signal so the best you can do is use effects to create a difference between hard panned signals, or you can double track the same part.

But my question is then for something like a DX7 or any hardware synth, how do the patches on there have stereo width? Like a tine piano sound on my DX7 sounds so nice and full and wide with no perceivable phase cancellation between each side. Specifically what is happening in the sound card of that DX7 that makes the sides different enough to not cancel out when spread wide hard L and hard R? Is it micro discrepancies in pitch? or timing?